#include <stdio.h>
#include <string.h>

// 指针控制字符串
int main()
{
    char a[100] = "hello world";
    char *p = a;
    *p = 'a';
    p[3] = 'b';
    int len = strlen(a);
    int min = 0;
    int max = len - 1;
    while(min < max)
    {
        char tmp = *(p + min);
        *(p + min) = *(p + max);
        *(p + max) = tmp;
        max--;
        min++;
    }
    printf("%s\n", a);
    return 0;
}

